Some prior inventions related to Dark Adaption embellishment to the Goldmann-Weekers machine as selected by a USPTO examiner are:    U.S. Pat. No. 2,247,653 January 1938 Feldman    U.S. Pat. No. 4,545,658 October 1985 Weiss    U.S. Pat. No. 5,080,478 January 1992 O'Brien    U.S. Pat. No. 9,572,485 February 2015 Jackson
Dark Adaption is the physical process whereby people lose full ability to see when going from a bright light situation to a dim light situation. People with Macular degeneration disease have weakened dark adaption function. The background of use of dark adaption to recognize macular degeneration disease largely began with the Goldmann-Weekers Dark Adaptometer machine developed about 1950. It dominates the history of this art and was in practical use until very recently but is now no longer manufactured. A series of other machines, based on the Goldmann-Weekers, were developed with various design features claimed to improve performance. These are represented in the list of inventions shown above. In order of the list the improvements included measuring the time for reappearance of a target object (Weiss), automation of the timing of the steps of the Goldmann machine (O'Brien) and use of sophisticated time sequence charts and of the “rod-cone intercept point” as a target factor on the y axis (Jackson).
All of these machines are fairly large and cumbersome although they can be moved as from one room to another or even to be placed in front of the patient but they are usually used from a fixed location. Even if designed for lightness, none would likely to be under 20 pounds as the target object and eye bleaching and other things are included within the machine. The only currently manufactured Dark Adaption machine weighs 46 pounds and measures 17×23×22. The traditional art of light dimming calls for reduction of current to the electric bulb or light source such as by a rheostat or by a light filter between the light source and the viewing eye as in sunglasses.